Ore-concentrating apparatus.



l. CALLOW.

ORE CONCENTRATING APPARATUS.

APPLICATION FILED MAR. 3. 1917.

Patented Jan. 15, 1918.

olocul UNITED STATES PATENT OFFICE.

JOHN I. OAIILOW, OF SALT LAKE'OITY, UTAH, ASSIGNOB 'I'O METALS RECOVERYCODANY, 0F AUGUSTA, MAINE, A CORPORATION OF MAINE.

OBE-GONOEIl'TBATING APPARATUS.

emu 0f um Rient- Patented J a 15, 1918.

Application illed Hatch 8, 1917. Serial No. 152,818.

To all 'whom it may concern:

Be it known that I, JOHN M. CALmw, a subject of the King of GreatBritain, residing at Salt Lake Cit in the county of Salt Lake and Stateof tah, have invented certain new and useful Improvements in Ore-Concentrating Apparatus, of which the following is a specification.

My invention relates to a flotation apparatus designed for theconcentration pf metallic ores by separating the metalliferous yparticles from the barren or rocky or nonmetalliferous constituents ofan ore pulp, composed of finely ground ore, water, and frothing agent;and 4my invention consists of the parts and the constructions,arrangements and combinations of parts which I will hereinafter describeand claim.

-This application is a continuation in part of and a substitute for myprior application, Serial Number 68,046, l'iled December 21, 1915, andrenewed October 5, 1917, Serial Number 195,208.

In the accompanying drawing forming part of this specification, Figure 1represents a vertical longitudinal sectional view of av flotation tankshowing one embodiment of my present invention. Fig. 2 illustrates anenlarged sectional fragment o the septum or blanket. Fig. 3 is a planview of The apparatus to which my invention relates is specificallyidentified with the art commonly known as flotation, wherein a certainpercentage of oil, or of two dissimilar oils, or an oil and an acid, oran oil and an alkali, or some substance having the property of producinga suitable froth, is mixed with finely ground ore and water and themixture then subjected to the action of a gaseous medium, preferably airunder pressure, whereupon a froth or suds is produced in which themetalliferous particles are re covered by iiotation.

In a more restricted sense, the present improvement has specificreference to a {iotation apparatus provided with a porous bottom orcovering for al gas compartment, the object of the improvement being,essentially, to provide an apparatus having such a bottom or coveringwherein the pores thereof are maintained in substantially their normalcondition and wherein the tendency of the pores to contractand finallyto close andimpede the passage of the gaseous medium therethrough isreduced to a minimum and l practically entirely eliminated.

Vrectangular form as also of' circular form,

and although I have shown in the present instance, for purposes ofillustration, a tank A having an inclined bottom, B it will beunderstood that the improvement which I am about to describe, isapplicable to or in connection with any of the above mentioned forms oftanks, or in connection with chambers or passages in which the gaseousmedium 1s introduced under pressure and discharged from the chamber intothe flotation cell or tank.

In the operation of pneumatic flotation cells (by which name the tanksabove referred to are commonly called,) or in fact, any pneumaticmachine which is used for floating mineral particles, or the like, andthereby separating the same from other and rejected material, andparticularly in.those cells or tanks, hollow arms, and like equivalentagencies, which employ blankets or fibrous coverings as the bottom orporous member, or as a wrapping or covering for perforated hollow arms,and through which blanket or covering a gaseous medium is designed to bedischarged under pressure, great difficulty has been experienced fromthe clogging or closing of the pores of the fibrous material of whichthe blankets 0r coverings are usually composed. Ordinarily, theseblankets or coverings, are made up of one or more thicknesses e ofloosely woven canvas, quilted into a mat or blanket, as shown in Fig. 3,by sewing in much the same manner aS the ordinary bed-quilts are made.When irst used, the loose weaving of these blankets or coverings,provide interstices which are of suiiicient size td permit the freepassage of air or other gaseous medium, but after a short time, saythree or four days, the fibers of the material become saturated andswell and the pores or interstices becomeous medium through the blanketincreases from, say l pounds up to three (3) or four (4) pounds as theblanket is continued in use, and at the end of say several weeks, theinterstices in the blanket become substantially clogged because of theminuteness of the interstices and the tendency of the settling materialto clog the same. Experience has shown that at the end of several weeks,the blankets have to be dried out and flogged with a carpet beater, orthe like, to make them operable; or, if this is not feasible, and theapparatus cannot be stopped for the purpose lof removing andrenewmg theblanket, recourse is had to the use of a stick, brush or paddle, withwhich to punch and beat the blankets to relieve them of the sedimentarydeposit and to thereby open the pores suiiciently to permit passage ofthe gaseous medium. y

With the large volume of air or other gaseous medium (which may be tencubic feet per square foot ofblanket per minute) passing through theblanket, it would not be expected that the blanket would becomesaturated, but that the issuing air, which is under considerablepressure, would tend to elevate the water in the pulp out of contactwith the blanket and thus prevent the fibers of which the blanket iscomposed from absorbing moisture. It is found, however, that this is notthe case, and the blankets in operation, do get wet, as their bers havea tendency to absorb moisture, and as a result, the fibers swell andtighten up the pores or yinterstices and thereby increase the resistanceto the passage of air, or gaseous medium.

Furthermore, in my experiments I have been somewhat surprised to find onsplitting open an old blanket (say one which has been in use for or 70days), to Vnd that its pores or interstices have been more or lessfilled with fine ore particles, or slimes, which have blocked thepassages or interstices. In another oase, where burned lime had beenadded to the ore pulp for the purpose of making the pulp alkaline (formetallurgical reasons well known in the art of'fioa'ting mineralparticles), I have found a ine deposit 4of lime between the plies of theblanket. In a still further case, when operating on a certain lime ore,which had previously been roasted, I found a cement like@ accretionformed on the surfaceof"b the blanket which in twenty-four hours wouldrenderthe blanket completely impervious to the passage of air at thepressures usually In my invention the apparatus is provided with ablanketv or septum B, which has been so treated as to render the berswholly or partially non-absorbent to water, or to an alkali, or an acid,and which treat- Lacasse ment I have found in practice, prevents theformation of the cement-like accretion, or the entanglements of theslimes within the meshes of the canvas, or other material, or betweenthe plies thereof. In fact, an apparatus provided with a blanket treatedas I will hereinafter describe, has proved conclusively that when Irender the canvas or the bers thereof wholly or partially non-absorbentto water, I eliminate the danger of the fibers swelling and therebyreduclng or closin the pores or interstices which are used fr thepassage of the gaseous medium, and hence the pores or interstices do notclog up, but remain in their'normal open condition and provide freeexits for the air or gaseous medium which lis admitted therethrough'intothe tank for the purpose of inducing in its combination with thefrothing agent, which is a constituent of the pulp under treatment, theformation 4of the air bubbles which serve as carriers for the mineralparticles of the ore and which gradually accumulate on the surface ofthe pulp and overflow 'vinto a suitable launder, or other receiver.

In producing theblanket forming a part of my apparatus I may use any ofthe well known operations and substances heretofore employed forwater-proofing fibers. For instance, such substances as wood-creosote; asolution of paraffin-wax and gasolene; rosin dissolved in ether;vaseline dissolved in gasolene; linseed-oil; neats-foot oil; or, infact, any of the substances capable of rendering the fibersnon-absorbent may be used to advantage; and hence my invention is notlimited to any particular means for the treatment of the blanket, or thefibers therestantial reduction of the size of the pores due toanexpansion or swelling of which .the blanket is composed.

My invention is distinctly related tothe metallurgical industryY and tothe so-called otation' processes which treat mineral-bearing pulps, asthe object of the treatment to which I refer is to render the blanketswhen combined with the other elements of a lotation apparatusless-absorbent to water and still leave their interstices free and openfor the passage intothe otation apparatus of the air or other,` gaseousmedium which is employed in flotation, processes.

The invention I have described is comparatively inexpensive and thepractical use in combination with flotation apparatus of a blankettreated as I have described has shown that the life of the blanket insuch apparatus is greatly prolonged and that the interstices remain openfor the passage of the gaseous medium into the apparatus and the iibersof there is not the tendency of the pores clogging during use by adeposit of any character.

The foregoing results are obtainable wherever the otation apparatus isprovided with a fibrous covering in association with an underlying orinclosed chamber C or passage into which a gaseous medium is admittedunder pressure and is designed to be discharged outwardly through thecovering and into a body of pulp containing particles which are to beseparated one from the other and which pulp also contains an agent whichinduces the formation of a froth, or a bubble column, when acted on bythe finely divided air admitted through said blanket or covering.

It will thus appear that my invention comprehends and includes anapparatus provided with such a covering as I have described lwhether thesame shall form a bottom which is inclined or horizontal and whether thetank or compartment be of rectangular, square, circular, or otherconfiguration, all of which are more or less common in the flotationart. Also, that the invention is broad enough to bring Within its scopeany apparatus having a gas receiving chamber or member, whose discharg!ing surface is formed or provided with such a fibrous porous coveringand where it is desirable and necessary that the pores of such coveringshould during operation be maintained in substantially their normalcondltion to provide for the emission of numerous jets of gas into theliquid body or pulp containing articles to be recovered, and where thebla eting of the pores because of the saturation of the fibers and theconse uent closing of said pores would have a ten ency to close thepores against the admission of the ine gaseous streams, as aboveindicated.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is 1. A flotation apparatus comprising, in

combination, a tank having a gas-receiving chamber, and a covering forsaid chamber, said covering bein formed of fibrous material porous for te admission of the gas into the tank, and having the capacity tosubstantially maintain its normal porosity when submerged in the liquidcontents of the tank.

2. In iotation apparatus, a tank having a gas-receiver and a porousfibrous covering between the same and the interior of the tank, saidcovering having means for subY stantially maintaining the porosity ofthe covering during the submergence of the lat ter in the liquidcontents of the tank.

3. In flotation apparatus, a tank having a gas compartment in its bottomand a fibrous blanket or septum forming a porous cov ering therefor,said blanket or septum being liquid repellent to maintain substantiallyits normal porosity when 1n use 4. A otation apparatus provided with awater-proofed or water repellent fibrous blanket or covering pervious toair through which air or other gas is introduced.

5. A flotation apparatus having a porous bottom for the intrcduction ofair or other gaseous flotation agent, said porous bottom being ofwater-proofed or water repellent fibrous material.

6. As an article of manufacture a metallurgical septum or blanketadapted for sub mersion and to form the bottom of a ota tion separatorycell and the top of a` cham ber containing a gaseous medium underpressure, said blanket consisting of lies of loosely-woven fibrousmaterial unite one to the other and having its upper surface made liquidrepellent the said blanket being of a nature to permit the passageupwardly therethrough of a gas under pressure from said' chamber.

In testimony whereof I affix my signature.

JOHN M. CALLOW.

